Motorcycles that have an engine, a transmission mounted rigidly to a single frame as a rigid member produce extreme vibration resulting in both frame and rider fatigue. In order to eliminate fatigue; manufactures like Harley-Davidson and others produce motorcycles that mount a rear suspension arm pivotally connected to a pivot member on a transmission assembly; the transmission assembly is connected to a engine to form a separate rigid power train unit; which is attached to a main frame through soft elastomeric mounts; the power train unit is interconnected by one or two stabilizer links to portions of the motorcycle; permitting movement in a vertical plane. These arrangements have reduced vibration input to the main frame and the rider; while maintaining integrity of the power train unit during transmission of driving forces between the engine and a rear wheel.
However, these designs have affected handling characteristics of the motorcycle due to the elastic connections between the power train unit and the main frame. Both the handling characteristic and the operating stability of the motorcycle are compromised, relative to a motorcycle configured with a single rigid frame. Because the soft elastomeric mounts: facilitate vertical movement of the power train unit relative to the main frame; and accommodate lateral deflection of the rear suspension arm in the horizontal plane; this results in weaving and wobbling; especially on long sweeping turns; which can be life threatening. This condition exists because the power train unit is interconnected with a portion of the motorcycle with less than three stabilizer links; less than three tie rods; less than three tie links; and therefore not anchored in the horizontal plane.
Motorcycle manufacturers do produce motorcycles with vibration isolation that interconnect the engine power train unit in respect to the main frame exemplified by U.S. Pat. No. 4,776,423 issued to Buell et al, (Buell '423). Buell '423 teaches a plurality of at least three tie rods interconnecting the engine and the power train unit with the main frame to mitigate lateral motion of the rear suspension arm in the horizontal plane. However, Buell '423 does not teach or suggest a solution to retrofit those motorcycles manufactured that have a power train unit interconnecting to the main frame with less than three tie rods.
A second exemplification in U.S. Pat. No. 6,213,240 issued to Buell et al (Buell '240). Buell '240 teaches at least three tie links interconnecting the engine and transmission assembly with the main frame to mitigate lateral motion of the rear suspension arm in the horizontal plane. However, Buell '240 does not teach a solution to retrofit those motorcycles manufactured that have less than three tie links interconnecting, the power train unit to the main frame.
Thus, challenges remain and needs persist to provide an apparatus for deterring the dangerous and life threatening instability of the motorcycles, manufactured with vibration isolation that have less than three stabilizer links interconnecting the power train unit (first portion of the motorcycle); to the main frame (second portion of the motorcycle) to prevent lateral movement.